It has conventionally been known that if carbon dioxide (carbonic acid anhydride: CO2) contacts the skin and the mucous membrane of the living organism, it penetrates into them only thereby, and it expands blood vessels around the parts of penetrated carbon dioxide and works to improve the blood circulation. Owing to this action of accelerating the blood circulation, it displays various physiological effects such as dropping of blood pressure, improving of metabolism or accelerating to remove pain substance or waste product. Further, it has also anti-inflammation and anti-bacterial. Therefore, carbon dioxide has recently been given attentions also from viewpoints of improving health or beauty other than the purpose of medical cares.
Carbon dioxide in the tissue of the living organism works to release oxygen carried in combination with hemoglobin in a red blood cell. Around parts at the high density of carbon dioxide, the red blood cell releases more oxygen. Thus, supply of oxygen to cells by the red blood cell is mainly controlled by carbon dioxide. In short, being without carbon dioxide, hemoglobin remains as combined with oxygen, and the cell becomes unable to receive oxygen. As is seen, carbon dioxide seems to have been a waste product resulted from action of the cell, however, it plays in fact very important roles in the living-body.
Further, in recent times, oxygen of high density has also widely been known as effective in activity of metabolism, fatigue recovery or stability of blood pressure.
By the way, for easing a symptom of disease in a respiratory system such as asthma or allergic rhinitis, an inhaler has been till now used for oral inhalation of a medicine or steam. As the inhaler, a jet system (compressor) inhaler has broadly been employed which makes use of an air flow at high speed to make fine droplets based on a spraying principle.